Antitussive activity of the Schisandra chinensis fruit polysaccharide (SCFP-1) in guinea pigs models

Schisandra chinensis (Turcz.) Baill. (S. chinensis), locally known as “Wuweizi”, has been used in the treatment of chronic cough as prescription medications of Traditional Chinese Medicine for thousands of years. However, the components of antitussive activity of S. chinensis and the mechanism are poorly understood. This study aims to investigate the antitussive activity of polysaccharides extracted from S. chinensis. S. chinensis fruit polysaccharide-1 (SCFP-1) was extracted by 95% ethanol and distilled water successively, and then the water extraction was isolated with chromatographic columns. The preliminary characterization of SCFP-1 was analyzed by gel permeation chromatography (GPC), gas chromatography–mass spectrometry (GC–MS) and some other recognized chemical methods. Antitussive potential of SCFP-1 was estimated at dose of 250, 500, and 1000 mg/kg respectively by peroral administration in a guinea pigs model with cough hypersensitivity induced by cigarette smoke (Chronic cough model) or acute cough guinea model induced by citric acid (Acute cough model). Also, the time-dependent antitussive effect of SCFP-1 were evaluated with acute cough model, and compared with codeine. The molecular of SCFP-1 was 3.18×104 Da, mainly being composed of glucose and arabinose (66.5% and 29.4%, respectively). Peroral administration of SCFP-1 at 250, 500, and 1000 mg/kg showed remarkable suppressive effects respectively on cough in both of chronic cough model and acute cough model. Meanwhile, inflammatory cell in BALF and some typical characteristics of nonspecific airway inflammation in animals exposed to CS was significantly attenuated after pretreatment with SCFP-1. The cough suppression of SCFP-1 (500 mg/kg) stablly lasted during the whole 5 h of time-dependent experiment, while no positive effect was observed after 300 min of oral administration of codeine. SCFP-1 is one of the antitussive components of S. chinensis.